Simple Recipes for Real Science

Tag: aquaponics’

I don’t usually buy farm-raised fish. Too many articles I’ve read tell me that the fish are polluted with chemicals and that fish-farming pollutes the environment. So, I dutifully check my Seafood Watch card and spend a little more on wild, sustainable, healthy fish.

When our Twin Cities blogging group, the Blog Pantry, met at Local D’Lish a few weeks ago, my eyes were instantly drawn to a fish tank set up at the back of the grocery store. The owner, Ann, told me they were setting up a small-scale aquaponics system that would use water from the fish tank to fertilize vegetables and herbs they were planning to grow in the store. I had seen a larger-scale version of the same thing on Will Allen‘s amazing 3-acre urban farm in the middle of downtown Milwaukee in the film “FRESH.”

Apparently, this type of closed loop, recycling system allows people to grow crops using less water while raising cleaner fish for food. Systems like these may revolutionize the way people farm in the future.

According to an article in the Christian Science Monitor,

“Recirculating aquaculture systems, or RAS, are closed-loop production systems that continuously filter and recycle water, enabling large-scale fish farming that requires a small amount of water and releases little or no pollution.

About 99.75 percent of the water in each unit is continuously cleaned and returned to the fish tanks. Manure filtered from the water during the recycling process is used as fertilizer on nearby farm fields. The nutrient-rich water can also be used to feed vegetables and herbs in large-scale aquaponics systems, which in turn filter the water for reuse.

One of RAS’s biggest benefits is its small “water footprint,” which opens the door to commercial fish production in areas with limited water resources. (The technology is proven for both fresh- and saltwater systems.)